Simply amazing work! Your concept is great. And this is to be truthful a very good improvement on the concept of the first artwork.
The details on the dragon are very life like, and you have put much work into drawing the veins on the wings which adds to the details and also makes it very natural.
The woman fighting the dragon had been drawn very nicely and just like the dragon looks very life like due to the large amount of details you have put in.
The warrior (/creature) on the dragon is very fierce indeed and the whole hollow look you have given it multiplies the horror and also highlights him in the background.
Overall its an amazingly detailed piece of work with a great concept and skillful digital painting techniques. Keep up the great work!